1. Field of the Invention
This invention relates to outboard marine engines. In particular, this invention relates to the cover or cowling for such an engine.
2. Description of Related Art
Outboard marine engines are generally self contained engines that have a propulsion device, such as a propeller, a turbine, or a jet propulsion unit, that is powered by an internal combustion engine or electric motor, for example. Outboard engines are generally mounted on small to midsize watercraft to provide driving power to the watercraft. The degree of sophistication of such engines varies widely from basic pull start engines to high-end electronically controlled engines, which can include an electric starting mechanism.
Outboard engines typically have three main sections: the top portion; the middle portion; and, the lower portion.
The top portion, known as the upper motor cover, houses at least a top portion of the engine. The upper motor cover may be made from a single piece of material or it may have a separate top known as the top cap. The top cap can have an opening therethrough to accommodate a pull rope to be used to start the engine.
The upper motor cover usually has an opening that functions as the air intake for the engine. This intake opening must be configured to prevent water from entering into the engine. To prevent entry of water, a tortuous conduit is generally provided in the upper motor cover to define an indirect path between the opening and the engine.
The middle portion is known as the lower motor cover. This portion houses the bottom of the engine, the exhaust housing, and the vertically oriented driveshaft. This portion also functions as the exhaust conduit. Exhaust gases are channeled from the engine to the exhaust housing, where they are exhausted to the atmosphere through a gasket or directly into the water through the gear case. The lower motor cover is typically made of two halves attached to each other along a vertical plane of the motor.
The lower motor cover is attached to the upper motor cover by fitting the upper motor cover onto the top of the lower motor cover. Conventionally, the joint between the upper motor cover and the lower motor cover is horizontally oriented and forms a straight line. The upper motor cover is secured to the lower motor cover by one or more locks with a seal therebetween. The locks are usually positioned at the front and/or the back of the cowling.
The lower portion is known as the gear case and includes the propeller. The gear case houses the propeller shaft and the transmission. The transmission consists of two bevel gears facing each other on the propeller shaft and a third bevel gear disposed between the first two bevel gears at the end of the driveshaft. The third bevel gear has an axis perpendicular to the propeller shaft. A mechanism is used to selectively engage one or the other of the bevel gears on the propeller shaft with the bevel gear on the driveshaft to control the direction of rotation of the propeller.
Prior art outboard engine cowlings are difficult to close when the engine is mounted on a watercraft. Since the joint is straight and horizontal, it is hard for an operator standing in a watercraft, especially when the watercraft is floating in a body of water, to align the upper motor cover with the lower motor cover to lock them together. Therefore, there is a need for an outboard engine with an upper motor cover that is easily closed and locked to the lower motor cover.
Prior art outboard engine cowlings are also difficult to lock once they are closed. Locks located at the back of the cowling are hard to reach from inside the watercraft, and locks located at the front of the cowling are hard to reach from behind the watercraft, when the watercraft is mounted on a trailer for example. Further, traditional upper motor cover locks are configured with a hook mounted on the lower motor cover and a hook-engaging member attached to the upper motor cover. If the upper motor cover is not perfectly aligned with the lower motor cover, it is difficult to latch the upper motor cover onto the lower motor cover and obtain a secure connection. Accordingly, there is a need for a cowling that provides an upper motor cover that is more easily locked onto the lower motor cover.
As there are two common versions of small to mid-size outboard engines, the electric starter type and the pull starter type, most outboard engines are available with two different upper motor covers, depending on the type of starter mechanism for that particular engine. The same is also true for large size outboard engines (more than 90 hp), although it is less common to have such engines with pull starters. However, the other parts of the engine, especially the other parts of the cowling, may be the same. This is also true for engines that are available, for example, as two-cylinder or three-cylinder versions of the same engine, which require different height covers. To accommodate this, manufacturers must have interchangeable upper motor covers for different versions of essentially the same engine, which adds to manufacturing and distribution costs. There is a need for reducing the added costs incurred by engines that are offered in different versions.
Another problem with conventional outboard engines is the lack of a light source. Large boats generally have electrical systems and accordingly have light sources. In fact, watercraft above a certain length are required by the U.S. Coast Guard to have lights. However, outboard engines are often used on small watercraft, typically small boats, especially without an on-board electrical system. Thus, these boats have no lighting, except for the U.S. Coast Guard required hand held flashlight. Some attempts have been made at incorporating lights to outboard engine cowlings, but these require that the cowling be specially molded to incorporate the light, which can be expensive and inconvenient for those who would like to retrofit their current outboard engine cowling. This poses at least an inconvenience when operating a boat in dark or dim lighting or when additional lighting would be desirable for making repairs or preparing for fishing, for example. At worst, this poses a hazard while operating the boat as there is no indication to other watercraft of the boat's presence. Thus, there is a need to provide an auxiliary light source for watercraft.